Product Overview

ManualsBrandsDwyer ManualsHVAC ControlsGas Pressure/Differential SPDT Pressure Switch, Manual Reset, w/ Mercury Switch (.5" - 5.0" W.C.)

DWYER INSTRUMENTS, INC. | dwyer-inst.com54

Differential Pressure Switches

PRESSURE

GAS PRESSURE SWITCH

Compact, Low Cost, 1.4 to 20 in w.c. Range

Reliable and convenient, the Series 1996 Gas Pressure Switch serves as a compact,

low cost switch for gas red furnaces and equipment. Pressure ranges for both models

are ideal for high or low gas pressure interlock. Visible set point and on-off indicators

add convenience in servicing. Use either NO or NC contacts on SPDT switch. Bottom

connection has both 1/8˝ female and 1/4˝ male threads for pipe nipple or coupling. Top

connection vents diaphragm chamber to outside or to furnace combustion chamber.

Mount switch with diaphragm in a horizontal position and gas pressure connection at

bottom. Used with natural, manufactured or LP gas.uv

FEATURES/BENEFITS

• Visible set point and on-off indicator simplies operation and trouble shooting

• Compact size and low cost make it ideal for gas red or gas equipment OEM

applications

APPLICATIONS

• Gas furnaces • Natural, manufactured or LP gas applications

3-1/8

[79.38]

3-1/2

[88.90]

1/8 [F] GAS PRESSURE CONNECTION

1/4 NPT EXTERNAL THREAD [ALTERNATE GAS CONNECTION]

VENT CONNECTION ON OPPOSITE SIDE

WINDOW AND VISIBLE ON-OFF INDICATOR

Ø7/8 [22.23] OPENING FOR 1/2 CONDUIT CONNECTION

REMOVABLE CONDUIT ENCLOSURE COVER

SPECIFICATIONS

Service: Air, natural and manufactured gas, LP gas.

Wetted Materials: Consult factory.

Temperature Limits: 32 to 110°F (0 to 43.3°C). -30 to 110°F (-34.4 to 43.3°C) for

dry gas or dry air.

Pressure Limits: 45 in w.c. (11.2 kPa) continuous; 10 psig (68.95 kPa) surge.

Switch Type: SPDT.

Electrical Rating: 15A @ 120-480 VAC, 60 Hz. Resistive 1/8 H.P. @ 125 VAC, 1/4

H.P. @ 250 VAC 60 Hz.

Electrical Connections: 3 screw type, common, normally open, normally closed.

Process Connections: 1/8˝ female NPT or 1/4˝ male NPT.

Vent Connection: 1/8˝ female NPT.

Mounting Orientation: Diaphragm in horizontal position. Consult factory for other

position orientations.

Set Point Adjustment: Screw type with visible indicator, inside conduit enclosure.

Weight: 1 lb 2.3 oz (349 g).

Agency Approvals: CE, CSA, FM, UL.

uExplosion-Proof Alternative: See page 55 (Series 1950)

vExplosion-Proof Alternative: See page 55 (Series 1950G)

Process Tubing Options: See page 453 (Gage Tubing Accessories)

The Series PG Gas Pressure/Differential Pressure Switch has a large sensitive

diaphragm and a reliable time proven mechanical design. For use with air and other

compatible gases, they feature excellent ±1% of full-scale repeatability, clear easy-to-

read scale and convenient external set point adjustment.

Application exibility is assured by a large variety of switching options including

SPST, SPDT, DPST and DPDT; opening or closing on increasing pressure, vacuum

or differential. PR and PRL models add manual reset operation on increasing

or decreasing pressure. Mercury switches or hermetically sealed snap switches

are available where high humidity would be a problem. If vibration or other factors

preclude the use of mercury, snap switches can be provided. Standard housing is

NEMA 1. Optional enclosures can be supplied for weather resistant and explosion-

proof requirements.

FEATURES/BENEFITS

• Clear easy-to-read scale and external set point adjustment simplies operation and

trouble shooting

• Large diaphragm provides accuracy for precise control

• Multiple switching options meet the design of applications

APPLICATIONS

• Natural, manufactured or LP gas applications

ADJUSTMENT

SCREW

Ø7/8 [22.23]

CONDUIT

CONNECTION

45°

30°

1/2 MALE NPT X

1/8 FEMALE NPT

PROCESS CONN.

1/8 FEMALE

NPT PRESS. CONN.

[101.6]

1/4

[6.35]

3/4 [19.05] CLEARANCE

FOR COVER REMOVAL

1-3/16 [30.16]

1-27/64 [36.12]

17/32 [13.49]

8-1/4

[209.55]

[3] Ø13/64 [5.16]

MOUNTING HOLES

EQUALLY SPACED ON

6-1/2 [165.10] B.C.

Ø7

[177.80]

Ø6-1/64

[152.78]

SPECIFICATIONS

Wetted Materials: Fairprene, brass,

steel, and aluminum.

Temperature Limits: -10 to 180°F (-23

to 82°C).

Pressure Limit: Single pressure use on

high side: Sustained pressure: 15 psig

(1.0 bar); Surge limit: 20 psig (1.4 bar).

Differential pressure use: Sustained

pressure, range P1: 2 psig (.14 bar);

Sustained pressure, range P2: 10 psig

(0.7 bar).

Enclosure Rating: General purpose.

Weatherproof and explosion-proof

optional.

Repeatability: ±1% of full range.

Switch Type: SPST mercury switch,

SPDT mercury switch, SPDT snap

switch, or SPDT hermetically sealed

snap switch. Optional DPDT.

Electrical Rating: SPDT mercury: 4A

@ 120 VAC/VDC, 2A @ 240 VAC/VDC.

SPST mercury: 6A @ 120 VAC/VDC, 3A

@ 240 VAC/VDC. SPDT Snap: 15A @

120 VAC, 8A @ 240 VAC, 0.5A @ 120

VDC, 0.25A @ 240 VDC. SPDT H.S.

Silver Snap: 5A @ 125/250 VAC, 30

VDC resistive. SPDT H.S. Gold snap: 1A

@ 125 VAC, 30 VDC resistive.

Electrical Connections: Screw type.

Conduit Connection: 7/8˝ (22.23 mm)

hole for 1/2˝ (12.7 mm) conduit hub.

Process Connection: 1/2˝ male NPT

and 1/8˝ female NPT used for single

positive pressure or high differential

pressure, 1/8˝ female NPT used for

single vacuum or low differential

pressure.

Mounting Orientation: Vertical.

Set Point Adjustment: External screw.

Weight: 4.5 lb (2 kg).

Deadband: See model chart.

Agency Approvals: FM, UL for mercury

switch models. UL only on snap switch

models.

GAS PRESSURE/DIFFERENTIAL PRESSURE SWITCHES

External Adjustment, Visible Dial, Hermetically Sealed Snap or Mercury Switch

SERIES PG | MERCOID

BY DWYER

SERIES 1996

USA: California Proposition 65

WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov

MODEL CHART

Model Range (in w.c.) Model Range (in w.c.)

1996-5 1.4 to 5.5 1996-20 4-20

MODEL CHART

Model Range Max. Deadband Switch Type Model Range Max. Deadband Switch Type

PG-153-P1

PG-153-P2

PG-3-P1

PG-3-P2

1-30 in w.c.

(.25-7.47 kPa)

0.5-5 psid

(0.3-.345 bar)

1-30 in w.c.

(.25-7.47 kPa)

0.5-5 psid

(.03-.345 bar)

1.9 in w.c.

(0.47 kPa)

0.4 psid

(0.38 bar)

1.3 in w.c.

(0.32 kPa)

0.3 psid

(0.21 kPa)

SPDT mercury

SPST mercury*

PG-7000-153-P1

PG-7000-153-P2

PG-7000-153HG-P1

1-30 in w.c.

(.25-7.45 kPa)

0.5-5 psid

(.03-.345 bar)

1-30 in w.c.

(.25-7.47 kPa)

4 in w.c.

(1.0 kPa)

.5 psid

(.035 bar)

4 in w.c.

(1.0 kPa)

SPDT snap

SPDT hermetically

sealed gold snap

*SPST switches shown are close on increase of pressure.

For open on increase of pressure replace 3 in middle of model number with 2. Example: PG-2-P1.

Pressure_2021.indb 54 7/15/20 8:18 AM